i did not evaluate joe biden, but if someone said to me listen we want you to do what s really required to know what happened there, you have to put dementia on the differential diagnosis. you have to say bizarre laughter, interrupting, if this were your dad or your grandfather, wouldn t you say, you brought him to me, keith, you ve got to tell me is he suffering with dementia, he can t seem to listen and laughing inappropriate. alisyn: here is how that doesn t ring true to me. people with dementia, he was rattling off. dave: the substance was solid. alisyn: it was faster and it wasn t all accurate, but he had a command of his conversation. see, that s the way he sees the issues. i m not diagnosing him, and haven t evaluated him psychological testing anybody s guess what it would show. not knowing every fact isn t required to diagnosed dementia and not saying he has it, i m